Premolded expansion joint



Aug." 24 1926.

1,597,273 A. C. FISCHER PREMOLDED EXPANSION JOINT vFiled Dec. 26 1925 I I L 4/ MM 0 I j N k4,

.VENTOR Patented Aug. 24, 1926.

UNITED STATES,

Amana'r c. rrscnaa, or crucaeo, rumors.

'rnanonn'nn axmnsron Jomr.

Application filed December 28, 1925. Serial li o. 77,877.

This invention relates to a mixture of bituminous substances and compressible cereal fibre stems in elongated strips, preferably rice straw, wheat straw, barley straw, oat straw, and like materials, which have a flat strong body structure, which are not subject to penetration and which more, or less retain a flattened form when compressed.

The preferred material is that of rice straw, because of its greater strength, and I use this material in proportions ranging from two (2) or three (3) per cent up to thirty (30) per cent, mixed with bituminous material in excess or seventy (70) per cent, i. e. ranging from seventy (70) to ninetyeight (98) per cent.

I also prefer to mix a finely divided material or fibre, which is readily secured from roofing scrap, and the percentages of the other fibre and the asphalt mass will then be decreased proportionately to thevolume of the latter material incorporated.

My invention relates articularly to a flat, elongated structure of the cereal straw, which acts as a strengthening web, as distinguished from flat grasses and other flat materials which might act as strengthening webs.

The cereal straws are not as apt to break along their horizontal lines as someof the other materials, and, therefore, make these materials the main factor in the strengthening means of the premolded joint.

While many of the straws will break apart into individual flattened strips of cereal straw, many of the members will remain doubled up and they will be pressed together in a flattened conditiongb'ut without adhesion of the interior. "fihis would, however, not detract from the strengthening web I formed by the fibre, whether in single flat strip or in a double cereal straw fibre. By reason of pressing same together and thus forming a double layer of straw jacketed on both sides by bituminous material, the

strengthening effect of the web would not be destroyed.

The use of straw as a reinforcing medium for expansion joints aids in developing the resilient and re-expanding qualities of the joint, due to the fact that the inner surface of the double walls of the straw are nonadhering. When straws are incorporated in the mix they-carry with them a volume of air between the non-adhering inner walls of each straw, thus developing a multiplicity of air pockets. These air pockets will cushion and react to the ressure developed from the outside of the joint, due to expansion of the concrete sections. As a. further advantage, upon contraction of the concrete sections the air pockets will aid in expanding the joint and in this way maintain the space accommodating the joint filled at all times re-' gardless of the contracted condition of the sections between which the joint is formed.

I might .also add a mineral substance, such as lime dust, talc, fullers earth, and the likefwhen the percentages will again be depreciated to make room for the additional matter. Likewise I may use a flow retarder or penetration retarder, such as, uncoagulated latex or dissolved rubber, either in smoked sheet or reclaimed state, or I may use a solidified oil. 1

The method of incorporating the rubber either in the latex or rubber solvent form retards penetration, and the method of securing t ese materials and placing them in a solvent condition are known to the art. Likewise the method of mixing the materials in suitable mixers of the larger type are known to the art, as disclosed by me pre' viously in various applications for Letters. Patent, and the art would know how to select such machines.

My invention relates to the structural interlacing of fibres to add strength to the mass, which, when mixed in various per centages is rolled into sheet form and cut into strips suitable for 'premolded expansion joints.

I do not wish to be limited to the cereal straw as long as it shows the peculiarity of being easily compressed to a flattened condition, ordinary wheat straw and rice straw are good examples of what is meant by such condition. The long straws are more or less cut up into smaller pieces of one or two inches, or even longer, but it would naturally be incorporated better in any lengths ranging from one to three or four inches.

The mixture is preferably combined by heating the asphalt to a liquid state, then incoworating the straw material, or by heat ing t e bituminous material to a liquid state and then later adding cereal straw, or it may be desirable to reduce the bituminousmaterial to a liquid state, adding a mineral dust, using vit as a penetration retarder. then mixin in the cereal straw.

A suitab e formula would be seventy-five (75) per cent of bituminous material and twenty-five (25) per cent cereal straw, or seventy-five (7 per cent bituminous material, twenty (20) per cent cereal straw and five (5) per cent mineral filler.

Another suitable formula would be eight (80) per cent bituminous material, five (5i per cent penetration retarder, such as dissolved rubber or a solid oil, and fifteen per cent cereal straw, or a suitable mixture would be composed of sixty (60) per cent bi tuminous material, twenty per cent finely divided fibre and twenty (20) per cent cereal straw.

Referring to the figures. Figure 1 represents a cross sectional, view of a bituminous premolded expansion joint, composed of bi- I tuminous material aand cereal straw It can readily be understood that the sections d-, which may be several inches 1n.len h or even less may easily be expande causing a cellular formation inside the joint, thus facilitating the action of the concrete slabs upon the sides of the expansion joint in expanding the joint back into position after compression.

Figure 1 illustrates to better, advantage the influences of the flat cereal straw upon the distributed areas of the mass a--, thus strengthening the walls of the joint by rea-- sod of the strips of cereal straw bexerting an influence over their respective areas.

I claim:

1. A preformed expansion joint for concrete construction, comprising a strip of hituminous material having straw incorporated therewith.

2. A preformed expansionjoint for concrete construction, comprising a strip of bituminous material having flattened straw 1n-- (zor orated therewith.

j 3. A preformed expanslon joint for consheets crete construction, comprising a strip of bituminous material having straw and finely divided fibrous material incorporated therewith.

4. A preformed expansion joint for concrete construction, comprising a strip of bituminous material having straw and comminuted mineral material incorporated therewith.

' 5. A preformed expansionjoint for concrete construction, comprising a strip of bituminous material having straw incorporated therewith as a reinforcing medium, and a filling material comprising finely divided fibrous matter and comminuted mineral material. 7 w

-6. Av preformed expansion joint strip for concrete construction, comprising bituminous material having less than fifty (50) per can};1 by weight of straw incorporated therewit 7 A preformed expansion joint for concrete construction, comprising a bituminous material which has been previously treated with a substance to retard its penetrating qualities, and having straw incorporated therewith. 8. A preformed expansion joint for concrete construction, comprising a'bituminous material which has been previously treated with a substance to retard its penetrating qualities, and having straw and finely -dividgd fibrous material incorporated therewit 9. The herein described method of producing expansion joint material which consists in heating bituminous material to reduce the same to a liquid consistency, IIllX- ing therewith a solidifying agent to retard the flow'and penetrating qualities thereof, incorporati'ng strawwith the mass thus mixed, rolling the material into sheets while .still warm and thereafter,- eutting said sheets into strips.

10. The herein described method of producing expansion joint material which consists in heating the bituminous material to reduce the same to a liquid consistency, and

incorporating strawtherewith in successive steps until the straw content of the mixture has reached a predetermined ratio with res ect' to the quantity of bituminous material, andthereafter rolling the mixture into strips.

Signed at Chicago, Illinois, this 22 day of Dec. A. D. 1925.

ALBERT orrsonnn.

and .fin'all'y cutting the sheets into 

